Abstract: A method for obtaining regenerated seedlings of Brassica campestris L. ssp. chinensis from embryonic tip tissues, including the following steps. A seed is inoculated to a germination medium for dark culture for 60 h. The testa, root tip, two cotyledons and middle growing point of the resultant germinated seed are removed, and an embryonic tip with a length of 3-5 mm is retained as an explant. The explant is sequentially subjected to low-temperature pre-culture in a pre-culture medium for 36 h, room-temperature shaking culture in a liquid bud induction culture medium for 10 min, and bud induction culture in a bud induction culture medium for 20 d. A regenerated plant with 5-6 leaves is transferred to a rooting medium for rooting culture for about 2 weeks, and a well-rooted plant is collected, and subjected to hardening and transplantation into a filed.

Abstract: A task platform display method, performed by a terminal, includes: receiving a start operation for starting a task platform corresponding to a first account; displaying, based on the start operation and the first account corresponding to a first task permission, a first task platform including a first number of first task options; receiving a platform switching operation for switching the task platform from the first task platform to a second task platform including a second number of second task options, the first number being less than the second number; and displaying, based on the platform switching operation and the first account corresponding to a second task permission, the second task platform.

Abstract: A method for obtaining regenerated seedlings of Brassica campestris L. ssp. chinensis from embryonic tip tissues, including the following steps. A seed is inoculated to a germination medium for dark culture for 60 h. The testa, root tip, two cotyledons and middle growing point of the resultant germinated seed are removed, and an embryonic tip with a length of 3-5 mm is retained as an explant. The explant is sequentially subjected to low-temperature pre-culture in a pre-culture medium for 36 h, room-temperature shaking culture in a liquid bud induction culture medium for 10 min, and bud induction culture in a bud induction culture medium for 20 d. A regenerated plant with 5-6 leaves is transferred to a rooting medium for rooting culture for about 2 weeks, and a well-rooted plant is collected, and subjected to hardening and transplantation into a filed.